1. Field of the Invention
The present invention relates to a device for preventing damage to shock susceptible products, preferably paper-rolls, which are subject to damage when fetched and/or delivered by means of a transport vehicle having a hoisting unit with a transfer device which is movable relative to said hoisting unit such that it is relocated and adapted to the product when pressed thereagainst by the transport vehicle, whereby the product preferably may be sucked onto a suction device forming part of the transfer device.
2. Description of the Related Art
U.S. Pat. No. 4,516,905 shows a transport vehicle having a hoisting unit with a transfer device. The hoisting unit and transfer device cooperate through a setting unit which is adapted by compulsion to retain the transfer device relative to the hoisting unit and alter the position of the transfer device relative to the hoisting unit in order to set the transfer device in position on the product to be fetched. However, it is difficult to quickly set the transfer device such that it attains exact position relative to the product, since the driver has problems in determining when the transfer device has reached exact position relative to the product for exact connection thereto, which is necessary if the transfer device includes a suction device for grasping the product. If the suction device is not correctly positioned relative to the product, the product can not be sucked onto said suction device.
The device shown in U.S. Pat. No. 3,207,348 obviates this problem, since the transfer device is not constrained to the hoisting unit but "hangs loose" in such a manner that it automatically adapts to the position of the product when pressed thereagainst by the transport vehicle. This is a decisive advantage since it is substantially easier and quicker to fetch and deliver the product. A problem of the prior art device however, is that the transfer device tilts forwardly when the product is lifted. This tilting movement may cause damage on the edges of the product during lifting thereof and if the product is a large paper roll, such damage can cause substantial losses because the damaged paper must be rejected. Furthermore, a product hanging forward on the hoisting unit may be damaged when putting it down after transportation.
According to the '348 patent, one has tried to eliminate this problem by tipping the mast on the transport vehicle backwards, but this involves a coarse setting that is difficult to determine, and which also may cause loading of the edges of the product during lifting or delivering thereof.